The developmental origins of adult disease hypothesis has gained strength as a powerful explanation for risk of some of the most prevalent and morbid human conditions. According to this theory, risk of disease in adulthood is initially induced by fetal responses to maternal conditions and exposures. Central to the developmental origins hypothesis is the concept of developmental plasticity which involves altered gene expression as a result of non-genomic modifications to DNA. Growing evidence supports the concept that developmental programming may occur from a window that spans periconception through postnatal life. Epidemiologic data supporting a relationship between assisted reproductive technologies, low birth-weight and rare conditions involving imprinted genes makes it plausible that additional exposures around the time of conception may also impact fetal growth. The full impact of impaired fetal growth may not be completely evident until years after birth when later developmental and reproductive milestones can be affected. We hypothesize that specific maternal exposures around the time of conception and in utero are associated with neonatal markers of metabolism, development and ovarian function. This study will measure several maternal exposures around conception and in utero that may impact developmental plasticity and post natal disease risk. Maternal levels of folate, vitamin B12, Vitamin D and the endocrine disrupting chemical Bisphenol-A will be measured. Cohorts of fertile women, infertile women seeking treatment will be recruited for study. At birth, neonatal weight and placental dimensions will be measured. Samples of cord blood from neonates will also be collected to measure biomarkers of metabolism (leptin, 1GF1, IFG2, Insulin, IGFBP3) and ovarian function (Anti-Mullerian Hormone). Results from this pilot study should help us design an appropriately powered clinical trial with the potential for the Reproductive Medicien Network to undertake.